The present invention relates to a toner image fixing device including fixing rollers which fix a toner image on a sheet of paper while gripping and transporting the sheet and a separating device which separates the sheet of paper wrapped on the fixing rollers by bringing a separating member into contact with the fixing rollers.
A fixing device in an image formation apparatus, such as an electrophotographic copying machine or electrophotographic printer, typically includes a heating roller and a press roller. A sheet of paper onto which a toner image has been transferred in a previous stage is gripped between the fixing rollers and the toner image is fixed on the sheet by heat and pressure.
In this fixing device, since the sheet is liable to stick to the heating roller, a separating device with a separating member is brought into contact with the heating roller. The sheet is forcibly separated from the heating roller by the separating device following fixing.
A conventional separating member is rotatably supported by a shaft which passes through a mounting hole formed in its mounting portion. Further, a tension spring has one end connected to a separating device main body made of plate metal and its other end connected to separating member, whereby a pawl portion of the separating member is urged into contact with the heating roller. Typically, a number of separating members are mounted on the same shaft.
The shaft is horizontally set by being inserted in mounting holes that are formed in support tab portions at opposite ends of the separating device main body and it has E rings fitted on its opposite ends to hold the shaft in place.
The separating device is mounted in the image formation apparatus by fixing the separating device main body by suitable mounting means to a mounting section.
With this conventional structure, however, it is not possible to remove any of the separating members unless one first dismounts the separating device, which is made as a unit, from the mounting section and then removes E rings and pulls out the shaft. Consequently, the work of disassembly for replacing the separating members is very troublesome and time-consuming. A further problem has been that the necessity of having the shaft increases the weight and constitutes an obstacle to make the device lightweight and also makes the cost higher.